WO2016101697A1

WO2016101697A1 - Microfluidics surface enhanced raman scattering transparent device structure and preparation method thereof

Info

Publication number: WO2016101697A1
Application number: PCT/CN2015/092799
Authority: WO
Inventors: 毛海央; 吴文刚; 欧文
Original assignee: 江苏物联网研究发展中心; 南京瑟斯检测科技有限公司
Priority date: 2014-12-26
Filing date: 2015-10-26
Publication date: 2016-06-30
Also published as: CN104515765A

Abstract

A microfluidics surface enhanced Raman scattering transparent device structure and preparation method thereof, the device structure comprising: a transparent active substrate (1605) and a microfluidic structure layer (1606) supported on the transparent active substrate (1605), and several detection micro-channels (1201) are disposed inside the microfluidic structure layer (1606), the detection micro-channel (1201) being in communication with a liquid inlet (1601) and a liquid outlet (1603) on the microfluidic structure layer (1606); the transparent active substrate (1605) and a surface of an area corresponding to the detection micro-channel (1201) each are provided with a metal nano-forest structure(601), the metal nano-forest structure (601) being between the liquid inlet (1601) and the liquid outlet (1603). The structure is compact, and can improve consistency of a detection signal of surface enhanced Raman scattering and shorten detection time and improve the signal to noise ratio of the detection signal of the surface enhanced Raman scattering, and can detect various substances simultaneously and in real time, with extensive application scope, and with security and reliability.

Description

Microfluidic surface enhanced Raman scattering transparent device structure and preparation method thereof

Technical field

The invention relates to a Raman scattering transparent device structure and a preparation method thereof, in particular to a microfluidic surface-enhanced Raman scattering transparent device structure and a preparation method thereof, and belongs to the technical field of semiconductor devices.

Background technique

The detection technique based on Raman scattering spectroscopy is a material structure analysis method that does not require marking of a sample to be tested, and has the characteristics of non-destructive and non-contact. With the development of laser technology and weak signal detection and reception technology, as a means to achieve molecular level detection of material structures, Raman scattering spectroscopy is expected to gain practical results in the fields of biological detection, disease diagnosis, environmental monitoring, and chemical analysis. A wide range of applications. However, due to the small Raman scattering cross section, the analytical sensitivity of Raman scattering spectroscopy detection is low, and Raman spectroscopy of many molecules or groups is difficult to obtain. Although the intensity of the Raman scattering spectrum can be increased to some extent by increasing the excitation laser power, for biological samples, a laser with too much intensity will destroy the biological activity of the sample, so many applications turn to the surface-enhanced Raman scattering effect. Increase the Raman scattering spectral intensity of the sample.

The surface-enhanced Raman scattering effect refers to a phenomenon in which a rough noble metal surface enhances a Raman scattering spectrum signal of a substance molecule adsorbed on the surface thereof upon excitation of incident light. The enhancement of the molecular Raman scattering signal is derived from the surface electron oscillation generated by the rough surface under the illumination of light. When the frequency of the incident light matches the frequency of the plasma of the metal itself, the electron oscillation reaches the maximum, so a metal surface is generated. An additional local electromagnetic field with the same frequency as the incident light, which covers the region where the incident light and the surface plasma are excited to be superimposed together. Since the Raman scattering of the molecule originates from the interaction between the polarization of the molecule itself and the external electric field, the molecule in this superimposed electric field is affected by the localized electromagnetic field in addition to the effect of the original incident electromagnetic field, thus stimulating The Raman scattering signal is also correspondingly enhanced. Compared to ordinary Raman scattering spectral signals, the intensity of the surface-enhanced Raman scattering signal is enhanced by multiple orders of magnitude, and even the detection of single-molecule Raman scattering signals can be achieved.

Up to now, a variety of methods for preparing open surface-enhanced Raman scattering active substrates based on nano-rough or nanostructures have been reported, including sol particle method, electrochemical oxidation reduction of metal electrodes, and metal nanospheres. Cloth method, gas-liquid curing student method and physical and chemical etching method, etc. When these test agents are distributed on these open active substrates, especially on nano-rough surfaces or nanostructures, soak-evaporation and titration-evaporation methods are generally employed. When the immersion-evaporation method is used, a layer of the analyte molecule can be uniformly adsorbed on the nano-rough surface or the nanostructure of the open active substrate, but the reagent amount required for this method is large, and the time required for the immersion often requires several Hours are even longer. When the analyte is distributed by titration-evaporation, the required reagent dose only needs to cover the entire surface of the active substrate in the horizontal direction, but the height may reach the order of millimeters, so the reagent dosage is still large; and the method is also the same It takes a long time to evaporate the solvent; in addition, when the method is used to distribute molecules on the open active substrate, the distribution of the molecules on the active substrate cannot be well uniformed due to the influence of the coffee ring effect and the like, thereby affecting Consistency of detected Raman scattering signals; In a perspective, the distribution of analyte molecules by evaporation is not suitable for in vivo detection of biomolecules that have special requirements for liquid environments.

The microfluidic surface-enhanced Raman scattering detection device can realize the detection of molecules in a liquid environment, and has the advantages of high measurement consistency and short test time. However, the reported SERS (Surface-enhanced Raman scattering) detection device has a complicated preparation process, and various process steps are involved, and the active substrate is generally prepared by using a material with visible light opacity, and then for a large-sized material. During the detection, the laser enters the device from the front, but the detection of the material covering the nano-forest structure often causes the laser to pass through the material and smoothly reach the nano-forest structure, thereby invalidating the detection of the device. In addition, the reported microfluidic SERS detection device has been exposed to material deposition, physical etching and the like throughout the process because the bonding regions for bonding other than the SERS active substrate are exposed, resulting in a large surface roughness of the region. Achieve effective bonding.

Summary of the invention

The object of the present invention is to overcome the deficiencies in the prior art, and provide a microfluidic surface-enhanced Raman scattering transparent device structure and a preparation method thereof, which are compact in structure and can improve the consistency of surface enhanced Raman scattering detection signals. The detection time is shortened, the signal-to-noise ratio of the surface-enhanced Raman scattering detection signal can be improved, the simultaneous real-time detection of various substances can be realized, and the detection of macromolecules, polymers and crystalline substances can be realized, and the adaptation range is wide. , safe and reliable features.

According to the technical solution provided by the present invention, the microfluidic surface-enhanced Raman scattering transparent device structure comprises a transparent active substrate and a microfluidic channel structural layer supported on the transparent active substrate, in the microfluidic channel structural layer a plurality of detecting microchannels are disposed, wherein the detecting microchannels are connected to the liquid inlet and the liquid outlet of the microfluidic channel structural layer; the surface of the transparent active substrate corresponding to the detecting microchannel is provided with a metal In the nano forest structure, the metal nano forest structure is located between the liquid inlet and the liquid outlet.

The transparent active substrate and nano-forest structure are permeable to laser light used to generate Raman spectral signals, and the transmittance ranges from 20% to 100%.

The number of the detection microchannels in the same microfluidic surface-enhanced Raman scattering transparent device structure is 2-20.

The thickness of the metal layer is 5 to 30 nm, and the diameter of each nanostructure in the nano forest structure is less than 300 nm, and the height of each nanostructure is 100 nm to 2 μm.

A method for preparing a microfluidic surface-enhanced Raman scattering transparent device structure, the method for preparing the Raman scattering transparent device structure comprises the following steps:

a providing a transparent active substrate, and introducing a plurality of metal nano-forest structures on the transparent active substrate by introducing a non-uniform etching through the gap;

b. providing a microchannel substrate, and preparing a microfluidic channel structural layer by using the microchannel substrate, wherein the microfluidic channel structural layer has a detection microchannel corresponding to the number of metal nanoforest structures, and detecting the microchannel The liquid inlet on the microfluidic channel structural layer is in communication with the liquid outlet;

c. Aligning the transparent active substrate with the microfluidic channel structural layer, the microfluidic channel structural layer is supported on the transparent active substrate, and the detecting microchannel is located directly above the metal nano forest structure.

An inlet pipe is arranged in the liquid inlet, and a liquid outlet pipe is arranged in the liquid outlet.

In the step b, when the material of the microfluidic channel structural layer is polydimethylsiloxane, the microfluidic channel junction The layer is prepared by the following steps:

2-a, providing a first microchannel substrate, coating a surface of the first microchannel substrate with a photoresist, and exposing the photoresist to obtain a desired photoresist pattern;

2-b, using the photoresist pattern on the first microchannel substrate as a mask, performing anisotropic etching on the first microchannel substrate to remove the photoresist pattern on the first microchannel substrate to Obtaining a microfluidic channel mold on the first microchannel substrate;

2-c, a prepolymer of polydimethylsiloxane is cast on the first microchannel substrate, and the prepolymer of polydimethylsiloxane is cross-linked and solidified to be in the first microchannel A polymer is obtained on the substrate; the polymer is peeled off from the first microchannel substrate, and a detection microchannel is formed at a position corresponding to the microfluidic channel mold in the polymer body, and is prepared at the both ends of the detection microchannel The opening of the polymer in which the microchannels are connected is detected.

In the step b, when the material of the microfluidic channel structural layer is silicon or glass, the microfluidic channel structural layer is prepared by the following steps:

2-a', providing a second microchannel substrate, and spin-coating a photoresist on a surface of the second microchannel substrate, and exposing and developing the photoresist to obtain a second microchannel substrate Required photoresist pattern;

2-b′, using the photoresist pattern on the second microchannel substrate as a mask, performing anisotropic etching on the second microchannel substrate, after removing the photoresist pattern on the second microchannel substrate, Obtaining the desired detection microchannel;

2-c', a liquid inlet and a liquid outlet are provided at both ends of each of the detection microchannels to obtain a microchannel structure layer.

The width of the metal nano-forest structure is not greater than the width of the detection micro-channel above the metal nano-forest structure; the height direction of the metal nano-forest structure is perpendicular to the transparent active substrate;

The metal nano-forest structure includes a nano-forest structure and a metal layer covering the nano-forest structure, the material of the metal layer being gold, platinum or silver.

The material of the transparent active substrate comprises glass, and the thickness of the glass is from 200 μm to 2 mm.

The present invention has the following advantages due to the above technical solutions:

1. Using the detection micro-flow channel and the metal nano-forest structure to achieve uniform distribution of the detected reagent on the surface-enhanced Raman scattering active substrate, thereby improving the consistency of the surface-enhanced Raman scattering detection signal, compared with the immersion-evaporation method and The detection time of the titration-evaporation method is significantly shortened;

2. The detection micro-channel can effectively reduce or even avoid the noise introduced by the test environment on the basis of uniform distribution of the molecules to be analyzed, and improve the signal-to-noise ratio of the surface-enhanced Raman scattering detection signal, thereby effectively ensuring the detection signal of the device. consistency;

3. Using a transparent active substrate, the laser can be incident from the back surface of the transparent active substrate into the detecting device, thereby obtaining good detection results without being affected by the size of the molecule or substance to be tested.

4. By designing different detection microchannels, one or more pairs of liquid inlets and outlets can be made, which can be used for the test of a molecule to be analyzed or the mixing and reaction of different analytes before and after the signal detection and comparison. .

5. The real-time detection of multiple materials can be simultaneously realized by designing a plurality of sets of metal nano-forest structure graphic regions on the transparent first substrate and by making a plurality of detection micro-flow channels.

In summary, the microfluidic surface-enhanced Raman scattering transparent device prepared by the invention can be widely applied to the fields of biological, chemical, medical, agricultural and the like for detecting liquid analytes and/or colloidal analytes and/or gas analytes. .

DRAWINGS

1 to 12 are cross-sectional views showing specific implementation steps of Embodiment 1 of the present invention, in which

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view showing the first substrate after cleaning according to the present invention.

Figure 2 is a cross-sectional view of the present invention after obtaining a hollow substrate using a second substrate.

Figure 3 is a cross-sectional view showing the first substrate and the hollow substrate of the present invention after being pasted.

Figure 4 is a cross-sectional view showing anisotropic etching of the present invention.

Figure 5 is a cross-sectional view showing the nano-forest structure on the first substrate of the present invention.

Figure 6 is a cross-sectional view showing the structure of a metal nano-forest obtained in the present invention.

Figure 7 is a cross-sectional view showing the transparent active body of the present invention.

Figure 8 is a cross-sectional view showing the first microfluidic channel substrate after cleaning according to the present invention.

Figure 9 is a cross-sectional view of the present invention after obtaining a microfluidic channel mold.

Figure 10 is a cross-sectional view of the present invention after casting a prepolymer.

Figure 11 is a cross-sectional view showing the polymer obtained in the present invention.

Figure 12 is a cross-sectional view showing the first microfluidic channel structure bonded to a transparent active body in the present invention.

13 to FIG. 15 are cross-sectional views showing specific implementation steps of a second embodiment of the present invention, wherein

Figure 13 is a cross-sectional view showing the second microfluidic channel substrate after cleaning according to the present invention.

Figure 14 is a cross-sectional view showing the second microfluidic channel structure of the present invention.

Figure 15 is a cross-sectional view showing the second microfluidic channel structure bonded to the transparent active material in the present invention.

Figure 16 is a schematic view showing the structure of the present invention.

DESCRIPTION OF REFERENCE NUMERALS 101-first substrate, 201-second substrate, 202-first substrate similar material layer, 203-punch-through structure, 301-adhesive tape, 302-introduction distance, 401-etching gas plasma Body, 501-nano forest structure, 601-metal nano-forest structure, 602-substrate metal layer, 701-transparent active body, 801-first microfluidic channel substrate, 901-microfluidic channel mold, 1001-prepolymer, 1101-polymer, 1102-polymer opening, 1201-detecting microchannel, 1202-first microfluidic channel structure, 1301-second microfluidic channel substrate, 1401-second microfluidic channel structure, 1601-in Liquid port, 1602-inlet tube, 1603-outlet port, 1604-outlet tube, 1605-transparent active substrate, and 1606-microfluidic channel structure layer.

detailed description

The invention will now be further described with reference to the specific drawings and embodiments.

As shown in FIG. 16 , in order to improve the consistency of the surface-enhanced Raman scattering detection signal and shorten the detection time, the signal-to-noise ratio of the surface-enhanced Raman scattering detection signal can be improved, and simultaneous real-time detection of various substances can be realized. The invention includes a transparent active substrate 1605 and a microfluidic channel structure layer 1606 supported on the transparent active substrate 1605, in which a plurality of detection microchannels 1201 are disposed, the detection microchannels 1201 and The liquid inlet 1601 and the liquid outlet 1603 of the microfluidic channel structure layer 1606 are connected to each other; the surface of the region corresponding to the transparent active substrate 1605 and the detecting microchannel 1201 is provided with a metal nano forest structure 601, the metal nano forest The structure 601 is located between the liquid inlet 1601 and the liquid outlet 1603.

Specifically, the width of the metal nano-forest structure 601 is not greater than the width of the detection micro-channel 1201 directly above the metal nano-forest structure 601; the height direction of the metal nano-forest structure 601 is perpendicular to the transparent active substrate 1605. The metal nano-forest structure 601 includes a nano-forest structure 501 and a metal layer overlying the nano-forest structure 501, the material of which is gold, platinum or silver. The thickness of the metal layer is 5 to 30 nm, and the diameter of each nanostructure in the nano forest structure 501 is less than 300 nm, and the height of each nanostructure is 100 nm to 2 μm.

The detection microchannel 1201 has a width of 1 mm and a depth of 10 to 50 μm, preferably 20 μm or 50 μm. The transparent active substrate 1605 and the microfluidic channel structure layer 1606 together form a device structure having a length of 10 mm. Generally, 2 to 20 detection microchannels 1201 are disposed in the microfluidic channel structure layer 1606. The width of the device structure is determined by the number of detection microfluidic channels 1201 provided, and as the number increases, the width of the device can be correspondingly widened. At the time of detection, laser light can be incident from the lower surface of the transparent active substrate 1605. To improve the detection effect, the transparent active substrate 1605 and the nano forest structure 501 are permeable to laser light for generating Raman spectral signals, and the transmittance is The range is 20%-100%.

At the time of detection, the liquid inlet pipe 1602 is placed in the liquid inlet 1601, and the liquid outlet pipe 1604 is built in the liquid outlet 1603 to inject the test agent into the detection microchannel 1201 through the liquid inlet pipe 1602, and the liquid can be discharged. Tube 1604 flows out.

In the specific detection, the test agent is injected into the detection microchannel 1201 from the liquid inlet tube 1602 inserted into the liquid inlet 1601 through a syringe, and the test agent flows from the liquid inlet 1601 to the liquid outlet 1603. The substance or molecule contained in the test agent is uniformly distributed in the detection microchannel 1201 as the fluid flows, because the bottom of the detection microchannel 1201 is the metal nano forest structure 601, so the test agent contains The substance or molecule will settle to the surface of the metallic nanoforest structure 601 after a few minutes of standing.

Since the substance or molecule contained in the test agent may have a large size, when it covers the metal nano-forest structure 601, the laser incident from the front cannot penetrate the substance or molecule to reach the surface of the metal nano-forest structure 601. Surface plasmon oscillation effects cannot be produced. In the embodiment of the present invention, in order to enable detection, laser light may be incident from the bottom surface of the transparent active substrate 1605. The bottom surface of the transparent active substrate 1605 is the other surface connected to the microfluidic channel structure layer 1606, and the transparent active substrate 1605 is transparent. The material ensures that the incident laser penetrates the transparent active substrate 1605 to the metal nanoforest structure 601.

The specific process is as follows: the transparent active substrate 1605 of the device is placed face up in the laser light path of the Raman scattering spectrum, and the laser penetrates the transparent active group 1605 to reach the metal nano forest structure 601, thereby generating a surface plasmon oscillation effect. Since the substance or molecule to be tested is adsorbed on the surface of the metal nano-forest structure 601, the surface plasmon oscillation effect is effective, and then the SERS line can be tested, and the test agent is obtained from the wave number corresponding to the position of the peak in the line. The composition of the substance or molecule contained in the substance, and the concentration of the substance or molecule is obtained from the intensity of the peak.

The microfluidic surface-enhanced Raman scattering transparent device structure can be obtained by the following specific steps of the first embodiment and the second embodiment. The experimental methods described in the following embodiments are conventional methods unless otherwise specified. The reagents and materials are commercially available unless otherwise stated.

Example 1

The first substrate 101 is made of a glass material, and the second substrate 201 is a glass piece; the first microfluidic channel substrate 801 uses a single crystal silicon wafer; the microfluidic channel structural layer 1606 material is polydimethylsiloxane. The first substrate 101 is used to finally obtain a metal nano-forest structure 601 on the surface thereof; the second substrate 201 is used to realize the hollow structure; and the first micro-flow channel substrate 801 is used to fabricate the micro-flow channel mold 901. The specific steps are:

Step 1. Prepare a surface-enhanced Raman scattering active substrate based on the metal nano-forest structure 601 on the first substrate 101, that is, prepare a transparent active substrate 1605, and at least one metal nano-forest structure 601 is disposed on the transparent active substrate 1605.

The specific steps are:

1-a, preparing and cleaning the first substrate 101, the second substrate 201 and the first microfluidic channel substrate 801;

Before the structural processing, the first substrate 101, the second substrate 201, and the first microfluidic channel substrate 801 are prepared and cleaned. As shown in Fig. 1, the prepared first substrate 101 is shown in Fig. 8, and the prepared first microfluidic channel substrate 801 is cleaned.

1-b, a through structure 203 is disposed on the second substrate 201, and a first substrate similar material layer 202 is disposed on a lower surface of the second substrate 201 to form a hollow substrate;

As shown in FIG. 2, a punch-through structure 203 is formed on the second substrate 201 by laser drilling. The punch-through structure 203 is a through hole penetrating the second substrate 201. The width of the punch-through structure 203 is 60 μm to 500 μm, preferably 120 μm. . Subsequently, a layer of amorphous silicon is deposited on the upper surface of the second substrate 201 as a first substrate-like material layer 202 by a plasma enhanced chemical vapor deposition (PECVD) technique, and the amorphous silicon layer has a thickness of 0.5 μm. 3 μm. Since the opening structure 203 has a large opening, the PECVD amorphous silicon does not fill the opening to close it. The conditions for preparing amorphous silicon by the PECVD method are as follows: a pressure of 2300 mTorr, a gas flow rate of 30 sccm of silane, an operating frequency of 13 MHz, and a power of 15 W.

1-c, the hollow substrate is pasted onto the first substrate 101 with the first substrate similar material layer 202 facing down, and the upper surface of the first substrate 101 and the lower surface of the hollow substrate are bonded by the adhesive tape 301. Introduce a certain distance between them;

As shown in FIG. 3, the hollow substrate obtained above is pasted onto the first substrate 101 with the first substrate-like material layer 202 facing downward, and the first substrate 101 and the second substrate 201 are bonded during the pasting process. The alignment edges are aligned with each other, and the edge of the substrate is also aligned with each other; when the two substrates are pasted with the adhesive tape 301, a certain distance is introduced between the two surfaces, that is, between the second substrate 201 and the first substrate 101. A distance is formed, that is, a distance 302 is introduced which will change the concentration of the etching gas plasma at different locations within the via.

1-d, etching the upper surface of the first substrate 101 through the through structure 203 on the hollow substrate by an anisotropic etching technique, on the upper surface of the first substrate 101 and the punch-through structure 203 Forming a nano forest structure 501 in the corresponding area;

As shown in FIGS. 4 and 5, the surface of the first substrate 101 is etched through the through structure 203 on the hollow substrate by an anisotropic RIE technique to obtain a nano-forest structure 501 of glass material. The nano-forest structure 501 of the obtained glass material has a height of 200 nm to 2 μm, preferably 1 μm. The gas used in the RIE first substrate 101 is an Ar/CF ₄ /CHF ₃ mixed gas, the flow rate is 300/15/35 sccm, the RF power is 450 W, the chamber pressure is set to 250 mTorr, and the etching time is 30-180 s. 60s.

1-e, sputtering a metal material on the first substrate 101 to which the hollow substrate is pasted;

As shown in FIG. 6, a metal material is sputtered on the first substrate 101 to which the hollow substrate is pasted. The metal layer is Ag and has a thickness of 5 to 30 nm, preferably 10 nm. Due to the presence of the hollow substrate, a mask layer is disposed on the first substrate 101 such that the metal layer is covered only on the surface of the nano-forest structure 501 to form the metal nano-forest structure 601, and in the first substrate 101 The remaining position of the upper surface is not covered with the metallic material, that is, the patterning of the metallic nano-forest structure 601 is formed. A substrate metal layer 602 is formed on the second substrate 201.

1-f, the hollow substrate is removed from the upper surface of the first substrate 101 after the sputtered metal layer, and the metal nano-particle is obtained in a region corresponding to the punch-through structure 203 on the upper surface of the first substrate 101. Forest structure 601.

As shown in FIG. 7, the hollow substrate is removed from the upper surface of the first substrate 101 on which the patterned metal nano-forest structure 601 is implemented, on the upper surface of the first substrate 101 and the punch-through structure. A pattern of the metal nano-forest structure 601 is obtained in the corresponding region of 203, and then a surface-enhanced Raman scattering transparent substrate is obtained, that is, a transparent active body 701 is obtained, and the transparent active substrate 1605 can be formed by using the transparent active body 701.

Step 2: preparing a microfluidic channel structure layer 1606 including at least one detecting microfluidic channel 1201; wherein the width of each of the detecting microfluidic channels 1201 is not less than that of the metal nanoforest structure 601 of the step 1 in the transparent The width occupied by the active substrate 1605;

Preparing the microfluidic channel structure layer 1606 includes the following steps:

2-a. After spin coating a layer of photoresist on the surface of the first microfluidic channel substrate 801, the obtained photoresist layer is pre-baked, then exposed on the photoresist layer, and obtained after development. Step 1-b corresponding to the photoresist pattern corresponding to the structure 203;

2-b, anisotropically etching the first microfluidic channel substrate 801 by using the photoresist pattern obtained in the step 2-a as a mask, and then removing the first microfluidic channel substrate 801 a photoresist pattern to obtain a microfluidic channel mold 901;

As shown in FIG. 9, after a layer of photoresist is spin-coated on the upper surface of the single crystal silicon wafer of the first microfluidic channel substrate 801, the photoresist layer is pre-baked and then applied to the photoresist layer. After the upper exposure, the photoresist pattern corresponding to the punch-through structure 203 of the step 1-b is obtained after the development; thereafter, the first microfluidic channel substrate 801 is performed by using the photoresist pattern as a mask. Anisotropic etching; removing the photoresist on the surface of the first microfluidic channel substrate 801 by using an oxygen plasma dry degumming method and a sulfuric acid/hydrogen peroxide wet gel removal method to obtain a microfluidic channel mold 901. In the embodiment of the present invention, the main purpose of the pre-baking is to dry the glue for exposure, and the specific process conditions of the pre-baking are well known to those skilled in the art, and are not described herein again.

2-c, pouring the microfluidic channel mold 901 obtained in the step 2-b with the prepolymer 1001 of the polydimethylsiloxane material to crosslink and cure the polydimethylsiloxane to obtain polydimethylsiloxane. The polymer 1101 of oxane, then the polymer 1101 of polydimethylsiloxane is stripped from the microfluidic channel mold 901, and at least one pair of polymer openings 1102 are formed at corresponding positions of each microfluidic channel to obtain The microfluidic channel structure layer 1606 containing at least one detection microfluidic channel 1201;

As shown in FIGS. 10 and 11, the first microfluidic channel substrate 801 with the microfluidic channel mold 901 is placed in a predetermined volume of the container, and the polydimethylsiloxane which is thoroughly mixed and has been removed from the bubbles is shown. The prepolymer 1001 is poured onto the mold and baked in an oven at 60 ° C for 60 minutes to crosslink and cure the polydimethylsiloxane to obtain a polymer 1101 of polydimethylsiloxane, which is then tested. Polydimethylene of microfluidic channel 1201 The siloxane polymer 1101 is peeled off from the first microfluidic channel substrate 801, and at least one pair of polymer openings 1102 are formed by mechanical perforation at corresponding positions of each microfluidic channel to obtain the microfluidic channel structural layer. 1606. In the embodiment of the present invention, the position of the polymer 1101 corresponding to the micro flow channel mold 901 can form the detection micro flow channel 1201, and the polymer opening 1102 includes the liquid inlet 1601 and the liquid outlet 1603, the liquid inlet 1601, and the liquid outlet. 1603 is respectively located at both ends of the formation detecting microfluidic channel 1201 and is in communication with the detecting microfluidic channel 1201. At this time, the polymer 1101 forms the first microfluidic channel structure 1202, and the microfluidic channel structural layer 1606 can be formed by the first microfluidic channel structure 1202.

Step 3: Align the transparent active substrate 1605 obtained in the step 1 with the microfluidic channel structure layer 1606 obtained in the step 2. The detection microchannel 1201 in the microfluidic channel structure layer 1606 is located on the transparent active substrate 1605. The microfluidic surface-enhanced Raman scattering transparent device is obtained directly above the upper metal nano-forest structure 601.

As shown in FIG. 12, the polymer 1101 of the polydimethylsiloxane with the polymer opening 1102 is placed face up with an oxygen plasma bombardment chamber with a power of 250 W and an oxygen flow rate of 30 sccm. The surface of the polymer 1101 of dimethylsiloxane is bombarded for 10 s, and the structural surface of the polymer 1101 of the polydimethylsiloxane is rapidly aligned with the upper surface of the transparent active substrate as shown in FIG. The bonding is effected by a chemical bond (as shown in FIG. 12) to obtain the microfluidic surface-enhanced Raman scattering transparent device.

Example 2

The first substrate 101 is made of a glass piece; the second substrate 201 is a single crystal silicon piece; the second micro flow channel substrate 1301 is made of a glass piece; and the micro flow channel structure layer 1606 is made of glass. The first substrate 101 is used to finally obtain a metal nano-forest structure 601 on the surface thereof; the second substrate 201 is used to realize the hollow structure; and the second micro-flow channel substrate 1301 is used to fabricate the micro-flow channel structure layer 1606.

The specific steps are:

1-a, preparing and cleaning the first substrate 101, the second substrate 201 and the second microfluidic channel substrate 1301;

Prior to the structural processing, the first substrate 101, the second substrate 201, and the second microfluidic channel substrate 1301 are prepared, and the substrate is cleaned. The prepared first substrate 101 is shown in Fig. 1, and the prepared second microfluidic channel substrate 1301 is shown in Fig. 13 and washed.

1-b, a punch-through structure 203 is disposed on the second substrate 201, and a first substrate-like material layer 202 is disposed on the lower surface of the second substrate 201 to form a hollow substrate;

As shown in FIG. 2, a layer of 500 nm - 3 μm silicon dioxide is grown on the surface of the second substrate 201 by a low pressure chemical vapor deposition (LPCVD) technique as an etch mask layer, followed by etching. a photoresist is spin-coated on the upper surface of the mask layer, and a stripe opening is formed on the photoresist layer by a photolithography process, and then the pattern of the strip-shaped opening on the photoresist is transferred to the etch mask layer by RIESiO2. Forming a strip-shaped opening pattern on the etch mask layer, that is, forming a substrate etch window; removing the surface of the etch mask layer by using an oxygen plasma dry stripping method and a sulfuric acid/hydrogen peroxide wet stripping method The photoresist is anisotropically etched by the DRIE technique, and the strip-shaped opening pattern on the etch mask layer is transferred onto the second substrate 201 to form a strip on the second substrate 201. The feedthrough structure 203 has a width of from 60 μm to 500 μm, preferably 120 μm. The remaining etch mask layer simultaneously forms a first substrate-like material layer 202. The etching gas used in the RIE silicon substrate is an alternating gas of C ₄ F ₈ and SF ₆ having a flow rate of 550 and 1000 sccm, an RF power of 2000 W, and a chamber pressure of 150 mTorr.

1-c. The hollow substrate is pasted onto the first substrate 101 with the first substrate-like material layer 202 facing down, and the upper surface of the first substrate 101 and the hollow substrate are pasted by the adhesive tape 301. Introducing a certain distance between the surfaces;

As shown in FIG. 4 and FIG. 5, the surface of the first substrate 101 is etched through the through structure 203 on the hollow substrate by an anisotropic RIE technique to obtain a glass material nano forest structure 501. The resulting glass material nanoforest structure 501 has a height of from 200 nm to 2 μm, preferably 1 μm. The gas used in the RIE first substrate 101 is an Ar/CF ₄ /CHF ₃ mixed gas, the flow rate is 300/15/35 sccm, the RF power is 450 W, the chamber pressure is set to 250 mTorr, and the etching time is 30-180 s. 60s.

As shown in Fig. 6, a metal material is sputtered on the first substrate 101 to which the hollow substrate is pasted, the metal layer being Ag having a thickness of 5 to 100 nm, preferably 50 nm. Due to the presence of the hollow substrate, a mask layer is disposed on the first substrate 101 such that the metal layer is covered only on the surface of the nano-forest structure 501 to form the metal nano-forest structure 601, and in the first substrate 101 The remaining positions of the upper surface do not cover the metal layer, that is, the patterning of the metal nano-forest structure 601 is formed.

As shown in FIG. 7, the hollow substrate is removed from the upper surface of the first substrate 101 on which the patterned metal nano-forest structure 601 is implemented, on the upper surface of the first substrate 101 and the punch-through structure. A pattern of the metal nano-forest structure 601 is obtained in the region corresponding to 203, and then a transparent substrate based on surface-enhanced Raman scattering is obtained, that is, a transparent active body 701 is obtained, and a transparent active substrate 1605 is formed by using the transparent active body 701.

Including the following steps:

2-a. After spin coating a layer of photoresist on the surface of the second microfluidic channel substrate 1301, the photoresist layer is pre-baked, and then exposed on the photoresist layer to obtain a solution. The punch-through structure 203 described in the step 1-b corresponds to the opposite photoresist pattern;

2-b, performing anisotropic etching on the second microfluidic channel substrate 1301 using the photoresist pattern obtained in the step 2-a as a mask, and then removing the second microfluidic channel substrate 1301 Photoresist pattern

2-c, at each of the microfluidic channel corresponding position to make at least a pair of liquid inlet 1601, the outlet port 1603, to obtain the microfluidic channel structure layer 1606 containing at least one detection microfluidic channel 1201;

As shown in FIG. 14, after a layer of photoresist is spin-coated on the upper surface of the glass sheet used as the second microfluidic channel substrate 1301, the photoresist layer is pre-baked and then exposed on the photoresist layer. After the development, a photoresist pattern corresponding to the punch-through structure 203 of the step 1-b is obtained. Thereafter, the second microfluidic channel substrate 1301 is oriented by using the photoresist pattern as a mask. The etching of the surface of the second microfluidic channel substrate 1301 is performed by using an oxygen plasma dry degumming method and a sulfuric acid/hydrogen peroxide wet degumming method to obtain a microfluidic channel structure 1401. The RIE second microfluidic channel substrate 1301 was made of a gas of Ar/CF ₄ /CHF ₃ mixed gas, a flow rate of 300/15/35 sccm, an RF power of 450 W, and a chamber pressure of 250 mTorr.

At least one pair of liquid inlets 1601 and a liquid outlet 1603 are formed by laser perforation at corresponding positions of each microfluidic channel, thereby obtaining a microfluidic channel structural layer 1606 containing at least one detecting microfluidic channel 1201.

Step 3: Aligning the transparent active substrate 1605 obtained in the step 1 with the microfluidic channel structure layer 1606 obtained in the step 2, and forming a micro-flow between the detecting microfluidic channel 1201 and the metal nano-forest structure 601 In the track body, the detecting microchannel 1201 in the microfluidic channel structure layer 1606 is located directly above the metal nano-forest structure 601 on the transparent active substrate 1605, that is, the microfluidic surface-enhanced Raman scattering transparent device is obtained.

As shown in FIG. 15, the microfluidic channel structure layer 1606 and the transparent active substrate 1605 are registered and bonded together by electrostatic bonding to obtain the microfluidic surface-enhanced Raman scattering transparent device.

The present invention forms a microfluidic surface-enhanced Raman scattering transparent device structure from a transparent active substrate 1605 and a microfluidic channel structure layer 1606 supported on the transparent active substrate 1605. The microfluidic channel 1201 in the microfluidic channel structure layer 1606 is formed. Directly above the metal nano-forest structure 601 on the transparent active substrate 1605, the transparent active substrate 1605 can allow visible light to pass through, and the microfluidic channel structure layer 1606 can be a visible light transmissive material or a visible light opaque material. The device structure and the preparation method thereof have the advantages of high yield, low cost, good detection consistency, no noise interference, and real-time monitoring of the microfluidic surface-enhanced Raman scattering transparent device, which can be used for the detection of large volume and crystal analytes. .

Claims

A microfluidic surface-enhanced Raman scattering transparent device structure, comprising: a transparent active substrate (1605) and a microfluidic channel structural layer (1606) supported on the transparent active substrate (1605), A plurality of detection microchannels (1201) are disposed in the microfluidic channel structure layer (1606), the detection microchannels (1201) and the liquid inlet port (1601) on the microfluidic channel structure layer (1606) and the liquid outlet ( 1603) connected; the surface of the region corresponding to the detection microchannel (1201) of the transparent active substrate (1605) is provided with a metal nano forest structure (601), and the metal nano forest structure (601) is located at the liquid inlet ( 1601) and the liquid outlet (1603).
The microfluidic surface-enhanced Raman scattering transparent device structure according to claim 1, wherein the transparent active substrate (1605) and the nano forest structure (501) are lasers for generating Raman spectral signals. Through transmission, the range of transmission is 20%-100%.
The microfluidic surface-enhanced Raman scattering transparent device structure according to claim 1 or 2, wherein the detecting microchannel (1201) is in the same microfluidic surface-enhanced Raman scattering transparent device structure. The number is 2-20.
The microfluidic surface-enhanced Raman scattering transparent device structure according to claim 3, wherein the metal layer has a thickness of 5 to 30 nm, and each nanostructure in the nano-forest structure (501) has a diameter of less than 300 nm. The height of each nanostructure is 100 nm to 2 μm.
A method for preparing a microfluidic surface-enhanced Raman scattering transparent device structure, characterized in that the method for preparing the Raman scattering transparent device structure comprises the following steps:

(a) providing a transparent active substrate (1605), and placing a plurality of metal nano-forest structures (601) on the transparent active substrate (1605) by introducing a non-uniform etching through the gap;

(b) providing a microchannel substrate, and preparing a microfluidic channel structural layer (1606) by using the microchannel substrate, wherein the microfluidic channel structural layer (1606) has the same number of metal nanoforest structures (601) The detection microchannel (1201), the detection microchannel (1201) and the microfluidic channel structure layer (1606) on the liquid inlet (1601) and the liquid outlet (1603);

(c) aligning the transparent active substrate (1605) with the microfluidic channel structure layer (1606), the microfluidic channel structure layer (1606) supported on the transparent active substrate (1605), and the detecting microfluid Road (1201) is located directly above the metal nanoforest structure (601).
The method for preparing a microfluidic surface-enhanced Raman scattering transparent device structure according to claim 5, wherein the liquid inlet (1601) is provided with a liquid inlet tube (1602) at the liquid outlet (1603) There is a liquid outlet tube (1604) inside.
The method for preparing a microfluidic surface-enhanced Raman scattering transparent device structure according to claim 5, wherein in the step (b), the material of the microfluidic channel structural layer (1606) is polydimethylsiloxane. In the case of an alkane, the microfluidic channel structure layer (1606) is prepared by the following steps:

(2-a) providing a first microchannel substrate (801), coating a surface of the first microchannel substrate (801) with a photoresist, and exposing the photoresist to obtain a desired Photoresist pattern

(2-b), using the photoresist pattern on the first microchannel substrate (801) as a mask, anisotropically etching the first microchannel substrate (801) to remove the first microchannel substrate ( a photoresist pattern on 801) to obtain a microfluidic channel mold (901) on the first microchannel substrate (801);

(2-c), a prepolymer (1001) made of polydimethylsiloxane is cast on the first microchannel substrate (801) to make a prepolymer of polydimethylsiloxane (1001) Cross-linking curing to obtain a polymer (1101) on the first microchannel substrate (801); peeling the polymer (1101) from the first microchannel substrate (801), and the polymer (1101) A corresponding microfluidic channel (1201) is formed at a position corresponding to the flow channel mold (901), and a polymer opening communicating with the detecting microchannel (1201) is prepared at both ends of the detecting microchannel (1201) ( 1102).
The method for preparing a microfluidic surface-enhanced Raman scattering transparent device structure according to claim 7, wherein in the step (b), when the material of the microfluidic channel structural layer (1606) is silicon or glass, micro The flow channel structure layer (1606) is prepared by the following steps:

(2-a'), providing a second microchannel substrate (1301), and spin-coating a photoresist on a surface of the second microchannel substrate (1301), and exposing and developing the photoresist to Obtaining a desired photoresist pattern on the second microchannel substrate (1301);

(2-b'), using the photoresist pattern on the second microchannel substrate (1301) as a mask, anisotropically etching the second microchannel substrate (1301) to remove the second microchannel substrate After the photoresist pattern on (1301), the desired detection microchannel (1201) is obtained;

(2-c'), a liquid inlet port (1601) and a liquid outlet port (1603) are provided at both ends of each of the detecting microchannels (1201) to obtain a microchannel structure layer (1606).
The method for preparing a microfluidic surface-enhanced Raman scattering transparent device structure according to claim 5, wherein the width of the metal nano-forest structure (601) is not greater than directly above the metal nano-forest structure (601) Detecting the width of the microchannel (1201); the height direction of the metal nanoforest structure (601) is perpendicular to the transparent active substrate (1605);

The metal nanoforest structure (601) includes a nanoforest structure (501) and a metal layer overlying the nanoforest structure (501), the material of the metal layer being gold, platinum or silver.
The method according to claim 5, wherein the transparent active substrate (1605) comprises glass, and the glass has a thickness of 200 μm to 2 mm.